.page-faq {
  --faq-index-w: 248px;
  --faq-radius: 22px;
  display: block;
}

/* 首屏 */
.page-faq .faq-hero {
  position: relative;
  isolation: isolate;
  padding-block: clamp(26px, 4.6vw, 58px) clamp(22px, 3.6vw, 40px);
}

.page-faq .faq-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background-image: repeating-linear-gradient(90deg, var(--line) 0 1px, transparent 1px 72px);
  opacity: 0.4;
  -webkit-mask-image: linear-gradient(180deg, #000 0%, transparent 82%);
  mask-image: linear-gradient(180deg, #000 0%, transparent 82%);
  pointer-events: none;
}

.page-faq .faq-hero__title {
  margin: 14px 0 0;
  max-width: 22ch;
  font-size: clamp(1.9rem, 5.6vw, 4.1rem);
  font-weight: 300;
  line-height: 1.16;
  letter-spacing: 0.04em;
  color: var(--ivory);
}

.page-faq .faq-hero__lede {
  margin: clamp(16px, 2.4vw, 26px) 0 0;
  max-width: 60ch;
  font-size: clamp(1rem, 1.2vw, 1.08rem);
  line-height: 1.85;
  color: var(--silver);
}

.page-faq .faq-hero__media {
  margin: clamp(18px, 3vw, 32px) 0 0;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  background: var(--panel);
  overflow: hidden;
}

.page-faq .faq-hero__media img {
  display: block;
  width: 100%;
  height: clamp(160px, 26vw, 330px);
  object-fit: cover;
}

/* 布局骨架：移动端单列，桌面端左索引 + 右面板 */
.page-faq .faq-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 52px);
  padding-block: clamp(32px, 5vw, 60px) clamp(56px, 7vw, 96px);
}

.page-faq .faq-panels {
  min-width: 0;
}

/* 分类索引 */
.page-faq .faq-index__label {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: var(--fs-index);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--silver);
}

.page-faq .faq-index__list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 2px 2px 10px;
  list-style: none;
  overflow-x: auto;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
}

.page-faq .faq-index__link {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 10px;
  min-width: 0;
  padding: 11px 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  color: var(--silver);
  font-size: 0.92rem;
  text-decoration: none;
  white-space: nowrap;
  scroll-snap-align: start;
  transition: color 0.2s ease, border-color 0.2s ease, background-color 0.2s ease;
}

.page-faq .faq-index__link:hover {
  color: var(--ivory);
  border-color: var(--accent, var(--gold));
  background: var(--panel);
}

.page-faq .faq-index__link[href="#qa-device"] { --accent: var(--ice); }
.page-faq .faq-index__link[href="#qa-path"] { --accent: var(--gold); }
.page-faq .faq-index__link[href="#qa-archive"] { --accent: var(--violet); }
.page-faq .faq-index__link[href="#qa-contact"] { --accent: var(--lava); }

.page-faq .faq-index__num {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  color: var(--accent, var(--gold));
}

.page-faq .faq-index__count {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--silver);
  opacity: 0.72;
}

/* 章节 */
.page-faq .faq-section {
  --accent: var(--gold);
  scroll-margin-top: calc(var(--rail-h) + 26px);
}

.page-faq .faq-section#qa-device { --accent: var(--ice); }
.page-faq .faq-section#qa-path { --accent: var(--gold); }
.page-faq .faq-section#qa-archive { --accent: var(--violet); }
.page-faq .faq-section#qa-contact { --accent: var(--lava); }

.page-faq .faq-section + .faq-section {
  margin-top: clamp(40px, 6vw, 68px);
}

.page-faq .faq-section__head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding-bottom: 14px;
  margin-bottom: clamp(18px, 2.6vw, 26px);
  border-bottom: 1px solid var(--line);
  transition: border-color 0.3s ease;
}

.page-faq .faq-section__head:hover,
.page-faq .faq-section:target .faq-section__head {
  border-bottom-color: var(--accent);
}

.page-faq .faq-section__num {
  font-family: var(--font-mono);
  font-size: clamp(1.4rem, 3vw, 2rem);
  line-height: 1;
  letter-spacing: 0.08em;
  color: var(--accent);
}

.page-faq .faq-section__title {
  margin: 0;
  font-size: clamp(1.15rem, 2vw, 1.5rem);
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--ivory);
}

.page-faq .faq-section__count {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: var(--fs-index);
  letter-spacing: 0.18em;
  color: var(--silver);
}

/* 章节配图 */
.page-faq .faq-figure {
  margin: 0 0 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--panel);
  overflow: hidden;
}

.page-faq .faq-figure img {
  display: block;
  width: 100%;
  height: clamp(160px, 28vw, 300px);
  object-fit: cover;
}

/* 阶段带 */
.page-faq .faq-stages {
  display: flex;
  gap: 10px;
  margin: 0 0 18px;
  padding: 14px clamp(12px, 2vw, 18px);
  list-style: none;
  overflow-x: auto;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: var(--panel);
  -webkit-overflow-scrolling: touch;
}

.page-faq .faq-stages__item {
  display: flex;
  align-items: baseline;
  gap: 4px;
  flex: none;
  padding: 8px 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  font-size: 0.9rem;
  color: var(--silver);
  white-space: nowrap;
}

.page-faq .faq-stages__num {
  font-family: var(--font-mono);
  font-size: 1rem;
  letter-spacing: 0.06em;
  color: var(--gold);
}

.page-faq .faq-stages__item--final {
  border-color: var(--gold);
  color: var(--ivory);
}

.page-faq .faq-stages__item--final .faq-stages__num {
  color: var(--gold-soft);
}

/* 折叠问答面板 */
.page-faq .qa {
  border: 1px solid var(--line);
  border-radius: var(--faq-radius);
  background: linear-gradient(180deg, var(--panel) 0%, var(--bg) 100%);
  transition: border-color 0.25s ease, box-shadow 0.25s ease;
}

.page-faq .qa + .qa {
  margin-top: 12px;
}

.page-faq .qa:hover {
  border-color: rgba(111, 227, 255, 0.5);
}

.page-faq .qa[open] {
  border-color: var(--ice);
  box-shadow: var(--shadow-lift);
}

.page-faq .qa__q {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: clamp(16px, 2.2vw, 22px) clamp(16px, 2.4vw, 26px);
  cursor: pointer;
  list-style: none;
  color: var(--ivory);
  font-size: clamp(0.98rem, 1.15vw, 1.06rem);
  line-height: 1.65;
}

.page-faq .qa__q::-webkit-details-marker {
  display: none;
}

.page-faq .qa__label {
  flex: 1;
  min-width: 0;
}

.page-faq .qa__id {
  flex: none;
  padding-top: 0.28em;
  font-family: var(--font-mono);
  font-size: var(--fs-index);
  letter-spacing: 0.14em;
  color: var(--gold);
}

.page-faq .qa__sign {
  position: relative;
  flex: none;
  width: 16px;
  height: 16px;
  margin-left: auto;
  margin-top: 0.42em;
}

.page-faq .qa__sign::before,
.page-faq .qa__sign::after {
  content: "";
  position: absolute;
  border-radius: 2px;
  background: var(--ice);
  transition: transform 0.25s ease, opacity 0.25s ease, background-color 0.25s ease;
}

.page-faq .qa__sign::before {
  left: 0;
  top: 7px;
  width: 16px;
  height: 2px;
}

.page-faq .qa__sign::after {
  left: 7px;
  top: 0;
  width: 2px;
  height: 16px;
}

.page-faq .qa[open] .qa__sign::after {
  transform: scaleY(0);
  opacity: 0;
}

.page-faq .qa[open] .qa__sign::before {
  background: var(--gold);
}

.page-faq .qa__body {
  margin: 0 clamp(16px, 2.4vw, 26px);
  padding: clamp(16px, 2vw, 20px) 0 clamp(18px, 2.4vw, 24px);
  border-top: 1px dashed var(--line);
}

.page-faq .qa__text {
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.85;
  color: var(--silver);
}

.page-faq .qa__steps {
  counter-reset: faq-step;
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-faq .qa__text + .qa__steps {
  margin-top: 14px;
}

.page-faq .qa__steps li {
  position: relative;
  padding-left: 34px;
  font-size: 0.95rem;
  line-height: 1.75;
  color: var(--silver);
}

.page-faq .qa__steps li::before {
  counter-increment: faq-step;
  content: counter(faq-step, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 0.14em;
  display: grid;
  place-items: center;
  width: 26px;
  height: 26px;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.04em;
  color: var(--gold);
}

.page-faq .qa__cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 16px;
  padding: 9px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
  color: var(--ice);
  font-size: 0.85rem;
  letter-spacing: 0.04em;
  text-decoration: none;
  transition: background-color 0.22s ease, color 0.22s ease, border-color 0.22s ease, transform 0.22s ease;
}

.page-faq .qa__cta:hover {
  background: var(--gold);
  border-color: var(--gold);
  color: #0A0E1A;
  transform: translateY(-1px);
}

.page-faq .qa__cta-arrow {
  font-family: var(--font-mono);
}

.page-faq a:focus-visible,
.page-faq summary:focus-visible {
  outline: 2px solid var(--ice);
  outline-offset: 3px;
}

@media (min-width: 960px) {
  .page-faq .faq-layout {
    grid-template-columns: var(--faq-index-w) minmax(0, 1fr);
    align-items: start;
  }

  .page-faq .faq-index {
    position: sticky;
    top: calc(var(--rail-h) + 22px);
    align-self: start;
  }

  .page-faq .faq-index__list {
    flex-direction: column;
    gap: 6px;
    overflow: visible;
    padding: 0;
  }

  .page-faq .faq-index__link {
    border-radius: var(--radius-md);
    white-space: normal;
  }

  .page-faq .qa__q {
    font-size: 1.04rem;
  }
}

@media (max-width: 520px) {
  .page-faq .faq-section__count {
    display: none;
  }

  .page-faq .faq-hero__lede {
    font-size: 0.98rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-faq .qa,
  .page-faq .qa__sign::before,
  .page-faq .qa__sign::after,
  .page-faq .qa__cta,
  .page-faq .faq-index__link,
  .page-faq .faq-section__head {
    transition: none;
  }

  .page-faq .qa__cta:hover {
    transform: none;
  }
}